The invention relates to a plug socket, particularly in a display instrument in a motor vehicle, which plug socket has a baseplate with a contact surface in order to place it on a printed circuit board and, in order to make contact with a respective conductor track on the printed circuit board, has a respective contact spring having a support region which is curved in the shape of an arc and projects beyond the contact surface of the baseplate when the baseplate is not seated on the printed circuit board.
Plug sockets of the above type are used, for example, to connect a combined instrument in a vehicle to a plug, so that it is connected to an electrical power supply and to data lines. To connect the plug socket to the printed circuit board, two mounting methods are customary. In the case of surface mounting, the baseplate of the plug socket is seated on the printed circuit board. In the case of plug-in mounting, the printed circuit board has an aperture through which the plug socket is pushed until the baseplate meets the printed circuit board from the insertion side. To date, differently designed plug sockets are required for these two types of mounting, and it has been found to be advantageous in both cases if the electrical connections between the plug socket and the conductor tracks do not have to be produced by means of solder connections. This is avoided by seating the contact region of a prestressed contact spring on the conductor track with which contact can be made for each electrical connection.
The invention is based on the object of providing a plug socket of the type mentioned in the introduction such that it is suitable both for surface mounting and plug-in mounting.
According to the inventon the baseplate has a respective contact surface on two opposite sides in order to seat it on the printed circuit board, and the contact spring has, in addition to the first support region curved in the shape of an arc, a second support region, which is curved in the shape of an arc towards the opposite side and, together with the first support region, forms the shape of an S lying on its side.
The effect achieved by this formation of the contact spring is that either one support region or the other support region of the contact spring makes contact with a conductor track, depending on whether plug-in mounting or surface mounting is being used. The plug socket according to the invention can therefore be used without modification for the two mounting methods. In addition, the plug socket according to the invention is suitable for SMD purposes (SMD=Surface Mounted Device) and can therefore be processed simply and cost-effectively. The plug socket""s flexibility, guaranteeing simple handling, minimal stockholding costs and also rapid and reliable mounting of the plug socket according to the invention, is of particular advantage in display instruments in motor vehicles, because this area requires production in very high numbers, with a very large and constantly changing range of variants and at very low costs.
For the purpose of precisely positioning plug sockets, the baseplate usually has positioning projections arranged on it which engage in corresponding apertures in the printed circuit board after the plug socket has been fitted. Exact positioning of the plug socket is advantageously possible in the case of both types of mounting if each contact surface has at least one respective positioning projection projecting from the plane of the contact surface.
The plug socket can also be secured very simply in the case of both types of mounting if each contact surface has at least one respective holding element projecting from the plane of the contact surface.
The plug socket could be a metal component, e.g. a stamped and bent sheet metal element. In accordance with one advantageous development of the invention, the plug socket can also be produced particularly cost-effectively in large numbers and additionally has electrical insulation if the plug socket is a plastic injection-molded part into which electrically conductive sockets or plug tabs are inserted or injection-molded.
The plug socket could conceivably be designed in a circular shape for the purpose of connection to a corresponding plug which likewise has a circular cross section. On the other hand, the plug socket has a particularly low space requirement and a high level of mounting reliability if, in accordance with another advantageous development of the invention, connecting sockets and/or plug tabs arranged in a row next to one another are arranged in a housing. In this context, it is possible to providexe2x80x94depending on the desired embodimentxe2x80x94sockets, into which tabs can be inserted, or tabs, onto which sockets can be plugged. It is also of particular advantage in this context if the end faces of the plug socket are designed such that a plurality of plug sockets can be lined up in a row in order to multiply the number of poles.